There has been known a vehicle seat like a second-row scat of a one-box car, which is capable of increasing a position adjustment range in a longitudinal direction by including a long-size slide rail. In such long-slide vehicle seat, it is typical to adopt a method of installing a slide rail on a vehicle floor in advance and mounting a vehicle seat on an upper rail of the slide rail. In such case, as disclosed in JP-A-2005-67557, there is a method of placing a vehicle seat so that bolts or positioning pins protruding upward on an upper surface of the upper rail are allowed to pass through holes provided on a lower surface of a cushion frame, and fixing them by bolts and nuts, or the like. In this method, there is a need for an operation of lowering the vehicle seat from above so as to allow the holes of the lower surface of the cushion frame to correspond to the bolts or the positioning pins while confirming the position of the bolts or the positioning pins on the upper rail from a lateral lower side of the vehicle seat.
In the vehicle seat adopting the mounting method as described above, there are cases where the weight of the vehicle seat is increased due to the vehicle seat having many functions, or a shield member is mounted to a seat cushion side in order to improve an outer appearance of the vehicle seat. In these cases, it is difficult to perform an operation of lowering the vehicle seat on the upper rail while adjusting the mounting position of the vehicle seat. Therefore. two people have to perform the operation or a special device is required for lifting or lowering the vehicle seat. As a result, there is a problem that the workability is poor.